Our Lady of the Underpass[1] was a salt stain and purported appearance of the Virgin Mary[2][3] under the Kennedy Expressway along Fullerton Avenue in Chicago[4][5] that was noticed in 2005. The site became a pilgrimage site for local Catholics[6] as well as a general curiosity. Later, it became a target for various acts of vandalism.[7][8] The Illinois Department of Transportation determined that the stain was likely formed by salt run-off.[8]
Tanya Saracho wrote a play about the event called Our Lady of the Underpass,[9][10][11] which was nominated for a Jeff Award.[12]